Cyclooctadiene compounds and process of preparing same

ABSTRACT

1. 1,5-CIS,CIS-CYCLOOTADIENE-1,2,5,6-TETRACARBOXYLIC ACID BISANHYDRIDE.

United States Patent 3 839 365 CYCLOOCTADIENE C,0MPOUNDS AND PROCESS OF PREPARING SAME Gerhard Martin Julius Schmidt, Meir Lahav, and Gad Patented Oct. 1, 1974 This may be irradiated either as the dry crystalline compound, advantageously spread out in a thin layer. It may also be irradiated while it is suspended in a suitable photochemically inert suspension medium, in which the trans,trans-muconic acid has a low solubility. The irradi- Friedma! f to :(eda Research 5 ated material is subjected to a thermal treatment, result- & DevehPment e ovot ing in the formation of the desired cyclooctadiene tetra- No Drawing. Filed May 14, 1970, Ser. No. 37,335

carboxylic acid. This may be done at the stage of evapora- Clarms priority, application Israel, May 14, 1969,

32,224/69 tron of the solvent. The material must be heated to about CL 7 61/26, 74; 3073 5 32 10 70 C. in order to obtain the desired result.

US. Cl. 260-3463 4 Claims The thus obtained cyclooctadiene tetracarboxylic acid is not separated. As will be shown in the following reaction scheme, it can be converted directly into a number ABSTRACT OF THE DISCLOSURE of desired products of reaction, which are novel com- The present invention relates to the preparation of novel pounds.

derivatives of cyclooctadiene tetracarboxylic acid. These The novel products of the present invention are useful are prepared by a photochemical dimerisation reaction as intermediates in organic synthesis. They are useful as of solid trans,trans-muconic acid, followed by a thermal intermediates and as monomers for various polymerization treatment, to result in the formation of cyclooctadiene reactions. They are of value in the production of polytetracarboxylic acid, which is converted into the desired imides, of pyrone type polymers, as curing agents for products, such as acids, anhydrides, esters, lactones and epoxides and for the production of alkyd resins.

the like. The reaction scheme can be shown schematically as follows:

HOOC

: h nooo coon HOOC COOH \COOH trans,trans- Compound I muconic acid (not isolated) 00 CO 00 CO 011.000 000cm W h- 0 M cn ooo COOCHa 0O 00 00 CO Compound 1T1 Compound II Compound VI l s l Laetone V CHaOOC COOCH; CHaOOC COOCHs CHaOOC COOCH: CHsOOC J-COOCH;

Compound IV SUMMARY OF THE INVENTION Compound VIII 0 o ooocn. 0

\ o 0 0cm Compound VII The invention is illustrated by the following examples, which are to be construed in a non-limitative sense:

Example 1 A quantity of 20 g. of crystalline trans,trans-muconic acid, spread out in a thin layer, was irradiated during 10 days with a Westinghouse sun lamp. After this period, there was added a quantity of 40 ml. methanol, stirred and filtered. The unreacted starting material (9.3 g.) did not dissolve, whereas the reacted material was obtained in the liquid phase. After evaporation till dry, during which the material was heated to 70 C., acetyl chloride was added. After reflux during 2 hours and subsequent Example 2 A quantity of 10 g. trans,trans-muconic acid was irradiated as in Example 1 and the reacted material was removed from unchanged starting material (4.65 g.) by solution in methanol. The methanolic solution was heated to above 70 C. and dry hydrogen chloride was introduced. After reflux for 4 hours, the reaction mixture was evaporated to dryness and the residue was taken up in ether. The resulting solution was dried over magnesium sulfate, filtered, evaporated and the residue was crystallizcd from ethyl acetate/ light petroleum to yield 1,2,5,6-[a] -tetracarbomethoxy 3,7 cis,cis-cyclooctadiene (Compound III), 3.2 g. M.P. 8588 C. The analytical sample had a M.P. of 88-90 C, v (KBr)-1730, 1640, 705; N.M.R. two signals centered at 4.1 and 5.9 and a singlet at 6.3 in the ratio 1:1:3.

Analysis.-Calculated for 'C H O :56.46, H: .9. Found: 0:56.43, H:5.7%.

From the mother liquor there separated an isomer of (III), probably 1,5/a/2,6/e/ tetracarbomethoxy 3,7- cis,cis-cyclooctadiene, 1.15 g., M.P. 144-145 C. (Compound IV). v (KBr)l730, N.M.R.-multiplets centered at 4.32 and 5.98 and a singlet at 6.28 in the ratio 1:1:3.

Analysis.--Calculated for C H O C:56.46, H: 5.9. Found: 0:56.51, H:6.01%.

Example 3 5 g. of the Compound II were boiled with 100 ml. of methanolic hydrogen chloride during 6 hours, yielding 4.5 g. of Compound III and 1.5 g. of Compound IV.

Example 4 Compound 11 was boiled with 60 percent sulfuric acid for 2 hours, the solution was poured on ice and extracted with ethyl acetate. The organic extract was dried, concentrated and chloroform was added. An acid lactone precipitated (Compound V). M.P. 290292 C.,

Analysis.-Calculated for C H O C:50.71, H: 4.26. Found: C:50.14, H:3.99%.

While the compound is an acid lactone, its structure could not be determined with certainty.

Example 5 Treatment of Compound III with methanolic ammonia at room temperature for 1 hour followed by evaporation till dry and crystallization from methanol yielded Compound IV, 3.0 g.

Example 6 Solid crystalline trans,trans-muconic acid g.) was irradiated as in Example 1, after which ml. of water were added so as to dissolve the reacted material. 4.0 g. of unreacted muconic acid were filtered off. The aqueous solution was evaporated to dryness and heated during the evaporation to about 75 C., after which the residue was refluxed for 3 hours with 40 ml. of acetyl chloride. After cooling, a solid precipitate was obtained (3.7 g.) which was filtered off and heated during 1 hour at C. After cooling and washing with a small quantity of methanol, there was obtained 1,5-cis,cis-cyclooctadiene 1,2,5,6-tetracarboxylic acid bisanhydride (3.6 g.), M.P. 260-265 C., Compound VI. The analytical sample was recrystallized from acetone, M.P. 265-268" C. (dependent on rate of heating). v,,,,,,,(KBr)-1860, 1790, 1660 cmr N.M.R. (deuterated DMSO) singlet at 'r 7.27.

Analysis.-Calculated for C H O C:58.07, H: 3.25. Found: C:58.36, H:3.04%.

Alternately, the aqueous filtrate from unreacted muconic acid was concentrated, 50 ml. xylene were added, and the mixture was boiled until all the water had distilled off. The remainder was cooled, the solid filtered off and crystallized from dirnethyl sulfoxide/methanol, yielding 3.4 g. of Compound VI.

Example 7 15 g. of trans,trans-muconic acid were suspended in 60 ml. water and irradiated for 5 hours with a Hanan Q 81 lamp (Vycor filter, internal cooling), with constant stirring. When the solid had completely dissolved, 30 ml. water were removed under reduced pressure and the remainder was treated with 75 ml. of xylene as in Example 6. All the water was distilled 01f azeotropically and excess xylene was removed under reduced pressure. The residue was washed with a little methanol and extracted with actone. The acetone extract deposited 6 g. of crystalline 1,5 cis,cis cyclooctadiene-l,2,5,6-tetracarboxylic acid bisanhydride. Addition of light petroleum precipitated a further 3.9 g. of this compound. Alternately Compound VI could be crystallized from dimethylsulfoXide/metha- 1101 as in Example 6.

Example 8 10 g. trans,trans-muconic acid were suspended in 500 ml. petroleum ether and irradiated during 5 hours as set out in Example 7. The petroleum ether was distilled off and the solid residue was taken up in 20 ml. water and filtered, leaving 2.0 g. of the unreacted starting material. Evaporation of the filtrate to dryness followed by xylene distillation as in Example 6 led to the formation of Compound VI, 4.15 g.

Example 9 Compound VI obtained in the preceding example, was boiled under reflux with methanolic hydrogen chloride for 16 hours. Excess of the reagent was removed under reduced pressure and the residue was purified by chromatography on kieselguhr. After elution with a mixture of benzene/chloroform there was obtained 1,2-dicarbomethoxy l,5-cis-cis-cyclooctadiene-S,6-dicarboxylic acid anhydride, M.P. 62-63 C. v (KB1')1785, 1840, 1715, 1650 cm.- N.M.R.-r 6.21 and 7.80.

Analysis.Calculated for C H O C=57.l4, H: 4.80. Found: C:57.l3, H:4.78%.

Example 10 Compound III was dissolved in ethyl acetate and hydrogenated at room temperature and atmospheric pressure with the aid of palladized charcoal, yielding 1,2,5,6- tetramethoxycarbonyl cyclooctane, Compound VIII. v (neat) 1740 cmr' N.M.R. 6.30 (singlet), 6.98 and 7.90 (multiplets) in 3: 1 :2 ratio.

What is claimed is:

1. 1,5 cis,cis cyclooctadiene-1,2,5,6-tetracarboxylic acid bisanhydride.

2. A process for producing the compound of claim 1 which comprises irradiating crystalline trans,trans-mu- 5 6 conic acid so as to elfect a photochemical dimerisation OTHER REFERENCES th t d t 21115130 reaf er heatlng the lrra lated substance to abou Lahav and Schmidt, J. Chem. Soc. 1967, Pp

312-17. 3. The process of claim 2 wherein the heating 1s ef- Wagner & 200k, Synthetic Organic Chem John Wiley fected by distilling off a solvent of high boiling point. 5 (1953),

4. The process of claim 3 wherein the solvent is xylene. JOHN D. RANDOLPH, Primary Examiner References Cited B. DENTZ, Assistant Examiner us. 01. X.R.

UNITED STATES PATENTS 260-468 L, 514 L, 343.3, 343.2 R, 78 TF, 2 EA; 204- 3,497,435 2/1970 Wimer et a1 204-158 R 158 R 

1. 1,5-CIS,CIS-CYCLOOTADIENE-1,2,5,6-TETRACARBOXYLIC ACID BISANHYDRIDE. 